Punch set for punching and riveting machines



June 26, 1945. MARCHANT PUNCH SET FOR PUNCHING AND RIVETING MACHINES Filgd May 2, 1944 Patented June 26, 1945 vPinion SE FOR Lee L.

PUNCHING MACHINES Marchant, Takoma Park, Md.,1assignor to AND iuvn'rmc Engineering and Research Corporation, Riverdale, Md., a corporationof Maryland Application Ma 2, 1944, Serial lio. 533,812 4'CI'aimsL (01.164-124) This invention relates to automatic punching and rivetin machines andto that part of such machines which operates to punch holes in the work, through-which the rivets arelplaced. It is the particular object of the. invention to provide a punch of newand improved structure whereby more efiicient operation of the punchandof the,

entire. machine is achieved. l

Other and various objects and features of novelty ofthe invention will be by. the following description andthe: a nexed drawing which, it will be understood; are only illustrative of the invention and impose no-limitation thereon not imposed by the appended.

claims. .1 v

Referring to the drawing',;,in whichsimilar reference numerals referto like parts,

Fig. 1 is a sectional view of a punching as sembly for a punching and riveting eluding a punch according to this invention;

Fig. 2 is a sectional view of a punch assembly of a different type from that disclosed in Fig. 1 and also including a punch according to this invention, and

Fig. 3 is an elevational view of a punch according to this invention.

Punching and riveting machines of the general type to which the invention relates are described and claimed in the patents to L. L. Marchant, No. 1,990,998, and to W. E. Marchant, No. 2,063,691. In the punching operation performed by such machines aligned holes are punched through superposed sheets of metal, the

punch is left in the holes to maintain their alignment, and a rivet is then passed into the holes, driving the punch out. Such a punch. assembly is illustrated in Fig. 1 and comprises a vertical, cylindrical device 2, which is known as the anvil, having an axial opening therethrough within which the punch to be described hereinafter is positioned. This axial opening has a part 4 of least diameter adjacent the upper end of the anvil, a part 6 of greatest diameter adjacent the lower end and a central part 8 of medium diameter. A stripper Ill surrounds the anvil and is normally held in a raised position by suitable means, such as a spring or, preferably, the fluid-pressure operated lever l2, whereby work sheets M which are to be punched and riveted may be positioned on the upper end thereof, as illustrated.

The new and improved punch structure provided by this invention comprises two separate parts, these being a follower or adapter 20, and a punch 22. The adapter, in the disclosed embodiment, comprises an integral, generally cylinmade apparent.

machine, 1111-,

, 3 the anvil and tion thanthe a raised position, as shown drical device having a cylindrical part 24 of greater cross-section-and a cylindrical part 26 of lesser cross-section which are, respectively, so constructed that they may be slidably received inthe co-axial openings 6 and 8 within the anvil. The. punch part 22, which is separate from the. adapter, comprises a cylindrical rod of substantially constant cross-sectional area throughout its len th and being of such cross-sectionalarea that it slidably fits-within the opening 4 within therefore is of smaller cross-secsmaller part 26 of the follower. When the punch parts 20, 22 are operatively positioned within the an, 1 they are intended in the normal operation of the machine, to occupy in Fig. l, or a lowered position. In the lowered the lower end of the adapter 28 rests on an adjusting screw .28. The punch is moved to raised posie tion by means ofa wedge 30 which is movable to a position beneath the adapter and is retractable from such position. The lengths of the two parts of the punch device are preferably such that when the punch is in raised position, as shown in Fig. 1, the upper end of the punch part 22 extends above the upper end of the anvil.

The typical cycle of operations of a punching and riveting machine of a type to which the in- Vention relates is as follows:

(1) The work sheets 14 are laid on the upper end of the stripper, the punch being supported in raised position by the wedge 30.

. (2) A die button engages the upper surfaceof the work sheets and forces them down over the punch, pushing the stripper downwardly against the hydraulic resistance of arm l2.

(3) The die button is raised, allowing the arm l2 to raise the stripper, work sheets and punch, the latter being raised by its frictional engagement within the punched holes in the sheet.

(4) The wedge 30 is withdrawn from beneath the punch.

(5) A rivet set places a rivet directly above the punch and forces it downwardly, pushing the punch to a lowered position in which its upper end forms part of th anvil, whereby further downward movement of the rivet causes it to be headed by the anvil.

In Fig. 2 of the drawing there is illustrated the use of my improved punch in a machine in which the work sheets are held by means engaging the upper surface thereof and the punch is driven upwardly through the sheets by means 40 which engage the lower end thereof.

Th parts may obviously have other cross-secposition of the punch v tional shape, than circular and the word "cy e drical" as used herein is to be understood as including such other shapes.

A defect of known, unitary punches has been that when the upper end of the punch becomes dulled by use in the punching operation the integral punch and follower must be withdrawn from the lower end of the anvil and replaced by a new punch. This requires that the adjusting screw 28 be moved and that a large supply of punches be available. It will be apparent, however, that in the use of the present invention the upper part 22 of the punch assembly may be simply and easily removed through the upper end of the anvil Without disturbing other parts of the assembly or the machine, after which it may be reversed end-for-end and re-inserted in the opening 4 in order to utilize both ends thereof before it must be finally removed for sharpenmg. a

- Other advantages which accrue from my invention will be apparent to those skilled in the art. While I have disclosed but one embodiment of the invention, other embodiments and sizes and relations of parts, as well as modifications of the embodiment disclosed, may be made without departing in any way from the spirit or scope of the invention, for the limits of which reference must be had to the appended claims.

I claim:

l. A punching device for a punching and riveting machine or the like comprising a unitary adapter part having a cylindrical part of greater cross-section adapted to be engaged on its free end by an operating member and having a second cylindrical part of lesser cross-section, and a cylindrical punch part separate from the adapter having substantially constant cross-sectional area throughout its length and being adapted to be engaged at its one end by the smaller part of the follower.

2. As a new article of manufacture, a punching device for a punching and riveting machine or the like comprising a member having two integral cylindrical co-axial parts of different cross-sectional area, and a separate cylindrical member of substantially constant cross-sectional area throughout its length.

3. A punching assembly'for a punching and riveting machine, comprising an anvil of integral construction having an axial opening therethrough which is of smallest cross-section at and adjacent the upper end of the anvil and of greatest cross-section at and adjacent the lower end of the anvil, and a twopart, two-element punch disposed within the opening in said anvil and comprising an adapter part slidable within the lower part of the opening and a punch part disposed within the upper partof the opening, the punch part being of substantially constant crosssection throughout its length.

4. A punching assembly for a punching and riveting machine, comprising an anvil of integral construction having an axial opening therethrough which is of smallest cross-section at and adjacent the upper end of the anvil and of greatest cross-section at and adjacent the lower end of the anvil, and a two-part, two-element punch disposed within the opening in said anvil and comprising an adapter part slidable within the lower part of the opening and a punch part disposed within the upper part of the opening, the punch part being of substantially constant cross-section throughout its length, the parts being of suchlength that th upper end of the punch part normally attends above the upper end of the anvil.

- LEE L. MARCHANT. 

